\documentclass{minimal}
\begin{document}

\part{testing}

\begin{dot2tex}[circo,tikzedgelabels,options=-t raw]
  digraph G {
    edge [lblstyle="above, sloped"];
    b1[label="$B1$",shape="box"];
    b3[label="$B3$",shape="doublecircle"];
  }
\end{dot2tex}

\chapter{testing}

\begin{dot2tex}[circo,tikzedgelabels,options=-t raw]
  digraph G {
    edge [lblstyle="above, sloped"];
    b1[label="$B1$",shape="box"];
    b3[label="$B3$",shape="doublecircle"];
  }
\end{dot2tex}

\section{testing}

\begin{dot2tex}[circo,tikzedgelabels,options=-t raw]
  digraph G {
    edge [lblstyle="above, sloped"];
    b1[label="$B1$",shape="box"];
    b3[label="$B3$",shape="doublecircle"];
  }
\end{dot2tex}

\subsection{testing}

\begin{dot2tex}[circo,tikzedgelabels,options=-t raw]
  digraph G {
    edge [lblstyle="above, sloped"];
    b1[label="$B1$",shape="box"];
    b3[label="$B3$",shape="doublecircle"];
  }
\end{dot2tex}

\subsubsection{testing}

\begin{dot2tex}[circo,tikzedgelabels,options=-t raw]
  digraph G {
    edge [lblstyle="above, sloped"];
    b1[label="$B1$",shape="box"];
    b3[label="$B3$",shape="doublecircle"];
  }
\end{dot2tex}

\end{document}
